The exhaust in question was done at Custom Exhaust Specialists @ Meadowbrook. its a custom pipe from the cat back, with a few little tricks in there, I just have to get this man computer literate, and he might post more often and give us an idea of what they changed. :D
I will see if I can get ahold of his dyno sheet too.
Kinda weird really, but I suppose, I have seen some really massive differences in stock LS1 engine outputs (up to 30rwkw variance) so I suppose 92-105kw is a good range for the stock engine.
Very interesting also, that he added a metal conditioner (roil) to his oil, and picked up 2 or 3 kw I think it was (have seen 8rwkw gain on a stock monaro too). There was a slight dip or two low in the rev range also, and they are now gone.
Its funny how I decided to buy a rolla for economy's sake, and here I am modding the thing before I have even signed on the dotted line.
Looks like its time to order me a Stivo, jesus, Im calling it that already.
JC